Under the current laws of the game a ruck/maul/scrum is over when the ball or ball carrier breaks the plane of the try line. That being the case once the ball touched the try line the ruck is over and therefore no offside line exists.

Eggman you are comparing 2 totally different situations. Firstly what the video ref did in that SA vs NZ game was incorrect in law but totally right in that the try wasn't allowed as it was a forward pass.
Secondly the can look at footage that happens on or behind the goal line including footage immediately leading up to the scoring of a try/touchdown. As the Italian player grabbed the Irish player as they were going over the goal line it is within the scope of the Video ref and they can rule on it. Shaun Veldsmen didn't and as far as i am concerned he was wrong not to.
Lastly there is no way that was accidental contact he put his fingers in the eyes of Healy and should get the maximum there is no room for that in any sport let alone Rugby.

The problem here is not the tackle or where it hit Paterson but that all parties on the field missed it, this is something the Assistant referees are meant to pick up. As they didn't the citing commissioner stepped in as they should.

In rugby these days player safety is paramount. Make a legal tackle or attempted tackle no problem, make a poor attempt and suffer the consequences of your actions.